It is known that during the transition period, which is three weeks before and three weeks after calving, ruminants experience a decrease in glucose levels, with the blood glucose level of cows being particularly low compared to other ruminants. During the transition period, the plasma glucose level drops from 60 to 70 mg/dl to about 45 mg/dl. Moreover, in the first few days after parturition, liver glycogen is depleted (Vasquez-Anon et al., J. Dairy Sci. 77(6):1521-1528).
Studies have also shown that heat-stressed ruminants experience an increase in glucose demands in skeletal muscle and cerebral metabolism. While heat-stressed ruminants experience a negative energy balance, adipose tissue is not mobilized and there is an increase in insulin sensitivity. This suggests that glucose is the preferred energy source necessary to minimize the negative impact of heat stress in ruminants (Rhodes et al J. Dairy Sci. 92(5):1986-1997).
U.S. Pat. Nos. 7,303,775 and 6,322,827 discloses carbohydrate ruminant feed energy supplements and methods of use. However, the '775 patent invention uses fructose as an energy source, and the methodology to protect the energy source is based on “fat coating.” As for the '827 patent, it the carbohydrate is chemically treated with formaldehyde to produce a protected carbohydrate.
U.S. Pat. Nos. 4,957,748, 5,789,001, and 6,221,380 discusses the use of Maillard reaction products, but as a method to produce ruminally inert lipids and proteins. Use of carbohydrates is limited to what is necessary to produce protected lipids and proteins. There remains a need for a product which includes a source of high quality rumen protected carbohydrates or blood glucose precursor for dairy animals, particularly during the transition period or during heat stress.